Radio-frequency identification (RFID) interrogators that conform to the International Organization for Standardization (ISO) ISO-18000-6C specification are unique in that they both transmit and receive simultaneously and on the same frequency. Many of these interrogators transmit and receive via a single antenna port. In such an RFID interrogator, some of the power from the transmitter reflects back to the receiver due to the practical antenna mismatch which may adversely affect the performance of the receiver portion of the RFID interrogator. For example, most RFID interrogators transmit +30 dBm (1 W) of output power. Even if an antenna has a respectable reflection loss of 15 dB, the receiver will need to tolerate a reflected power of +15 dBm. In order to tolerate this self-jammer, certain considerations may be provided for in the receiver front end that allow the system to tolerate such reflections. In order for the receiver to tolerate such high input signal levels of the self-jammer signal, the receiver typically utilizes a supply voltage of +5 V or greater. Many RFID interrogators, however, do not have an available +5 V supply, and/or may operate at a lower power, such as portable, hand-held RFID interrogators.
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.